Search Results for author: P. -A. Absil

Found 11 papers, 4 papers with code

Infeasible Deterministic, Stochastic, and Variance-Reduction Algorithms for Optimization under Orthogonality Constraints

no code implementations29 Mar 2023 Pierre Ablin, Simon Vary, Bin Gao, P. -A. Absil

Finally, our experiments demonstrate the promise of our approach to an array of machine-learning problems that involve orthogonality constraints.

Riemannian optimization

Symplectic eigenvalue problem via trace minimization and Riemannian optimization

2 code implementations7 Jan 2021 Nguyen Thanh Son, P. -A. Absil, Bin Gao, Tatjana Stykel

We address the problem of computing the smallest symplectic eigenvalues and the corresponding eigenvectors of symmetric positive-definite matrices in the sense of Williamson's theorem.

Optimization and Control Spectral Theory 15A15, 15A18, 70G45

A Grassmann Manifold Handbook: Basic Geometry and Computational Aspects

no code implementations27 Nov 2020 Thomas Bendokat, Ralf Zimmermann, P. -A. Absil

The Grassmann manifold of linear subspaces is important for the mathematical modelling of a multitude of applications, ranging from problems in machine learning, computer vision and image processing to low-rank matrix optimization problems, dynamic low-rank decompositions and model reduction.

Numerical Analysis Numerical Analysis Differential Geometry 15-02, 15A16, 15A18, 15B10, 22E70, 51F25, 53C80, 53Z99

Alternating minimization algorithms for graph regularized tensor completion

1 code implementation28 Aug 2020 Yu Guan, Shuyu Dong, P. -A. Absil, François Glineur

Furthermore, based on the Kurdyka-{\L}ojasiewicz property, we show that the sequence generated by the proposed algorithm globally converges to a critical point of the objective function.

Assessment of COVID-19 hospitalization forecasts from a simplified SIR model

no code implementations20 Jul 2020 P. -A. Absil, Ousmane Diao, Mouhamadou Diallo

Moreover, we observed that, when the model is trained on a suitable three-week period around the first hospitalization peak for Belgium, it forecasts the subsequent two months with mean absolute percentage error (MAPE) under 4%.

Riemannian Optimization on the Symplectic Stiefel Manifold

2 code implementations26 Jun 2020 Bin Gao, Nguyen Thanh Son, P. -A. Absil, Tatjana Stykel

The symplectic Stiefel manifold, denoted by $\mathrm{Sp}(2p, 2n)$, is the set of linear symplectic maps between the standard symplectic spaces $\mathbb{R}^{2p}$ and $\mathbb{R}^{2n}$.

Optimization and Control Dynamical Systems

On a minimum enclosing ball of a collection of linear subspaces

no code implementations27 Mar 2020 Timothy Marrinan, P. -A. Absil, Nicolas Gillis

By scaling the objective and penalizing the information lost by the rank-$k$ minimax center, we jointly recover an optimal dimension, $k^*$, and a central subspace, $U^* \in$ Gr$(k^*, n)$ at the center of the minimum enclosing ball, that best represents the data.

VIP: Vortex Image Processing package for high-contrast direct imaging

1 code implementation17 May 2017 C. A. Gomez Gonzalez, O. Wertz, O. Absil, V. Christiaens, D. Defrere, D. Mawet, J. Milli, P. -A. Absil, M. Van Droogenbroeck, F. Cantalloube, P. M. Hinz, A. J. Skemer, M. Karlsson, J. Surdej

We present the Vortex Image Processing (VIP) library, a python package dedicated to astronomical high-contrast imaging.

Instrumentation and Methods for Astrophysics

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